Means for automatically selecting the highest or lowest pressure from a group of changing fluid pressures



Filed Feb. 19, 1954 GAskrr Aug. 4, 1959 A. c. s'rucKl 2,897,834 MEANS FoR AUFGMATIGALLY SELEGTING TRE HIGHEST oR LowEsT FREssuRE FROM A GRouF oF CHANGING FLUID PREssUREs 2 Sheets-Sheet 1 Covell PLAT;

2% CEM Aug. 4, 1959 2,897,834

A. C. STUCKI MEANS FOR AUTOMATICALLY SELECTING THE HIGHEST OR LOWEST PRESSURE FROM A GROUP OF CHANGING FLUID PRESSURES Filed Feb. 19, 1954 2 Sheets-Sheet 2 Punssun Fm umvlwm. Pneummz. Cowrnouens a 's a a A A A ...wv-M www Q 5 s `J j Lowzsf Pnessunr. `J

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.7@ A l A 4 l A 4 l DMPHRAGM B B Pnessuns. FROM lunlvmum. PNeuM/rrlc. CourRoLLElzs /NveNrvn MEANS FOR AUTOMATICALLY SELECTING THE HIGHEST OR LOWEST PRESSURE FROM A GROUP OF CHANGING FLUID PRESSURES Arthur C. Stucki, Rockville, Md. Application February 19, 1954, Serial No..411,324

Claims. (Cl. 137-101) My invention relates to a system for the automatic selection and transmission of the lowest or the highest of a group of variable pressures.

One purpose of such a system is to gather various branch line pressures from a group of conventional pneumatic controllers and to select the lowest or highest pressure, as desired, for transmission to another mechanism to be controlled. The proper control of the latter mechanism being a function of the extreme demand of the individual branch line pressures.

For example, consider a heating system wherein individual zones of temperature are handled by a pneumatic thermostat in each zone. Each thermostat, upon a fall in temperature, causes a greater pressure to be transmitted to an individual damper motor which in turn allows more warm air, and less cold air, to enter that zone. A relay system such as mine can constantly transmit thehighest pressure from 4any of the thermo-stats to a steam valve in order to allow only enough steam to heat the common air supply to the minimum temperature required to heat the coldest Zone, therefore saving ya considerable amount of heat in many applications.

The above illustration is merely -a simple example of what such a system can do. The system has many applications in temperature, humidity, pressure, and other controlled processes.

Systems for doing the same thing have been in use for many years and are being manufactured by several corporations. My particular system for the selection of the highest or the lowest pressure is new, novel and much more simple.

In the drawings:

Figure 1 is a plan View showing a plurality of unit housings secured together, and partly broken away;

Figure 2 is a vertical cross section taken on the line 2 2 of Figure l, looking in the direction of the arrows;

Figure 3 is a schematic view of the plural unit system connected to select and transmit the lowest of a plurality of pressures; `and Figure 4 is a schematic View of the plural unit system connected to select and transmit the highest of a plurality of pressures.

My system is composed of a plurality of single basic unit housings, as shown in Figures 1 and 2. Each housing unit has six (6) ports and IanV internal one way valve. The complete system is built by attaching a plurality of individual units to one another, using one unit for each pressure source from which pressure is to 'be selected. Certain ports are plugged, `as required for the selection of the lowest or highest pressure, and the first unit (as shown at the left) is iitted with an oriiice 17 to bleed fluid into or out of the system, respectively.

The housing units I, II and III, etc. are open to one another through a single port 7 in each of the gaskets 8 which are placed between each of the connected units. These gasket ports 7 are turned to be in alignment with either ports 1 and 4, or ports 2 and 5, thus connecting 2,897,834 Patented Aug. 4, 1959 ice either chambers A or chambers B of adjacent housing units, as the application requires.

Referring :to Figure 2, the housing units I, II, III etc. are identical in construction, the left and right sidewalls of the housings each being provided with a pair of ports, l and 2 in the left hand wall, and 4 and 5 in the right hand wall. The bottom of each housing is provided with a port 6 and the housing top is sealed with a cover plate having a port 3 therein. The side wall ports 1, 2, 4 and 5, are positioned so that when the housing units are placed side by side, ports'4 and 5 in the right hand wall of the unit I will be in -alignment with ports 1 and 2 in the next succeeding unit Il, and so on. In stacking the housing units so as to measure the highest or lowest of a plurality of pressures, the units I, II, III, etc. are each separated by a gasket 8 having a single aperture 7 therein- Thus, either ports 2 and 5 may be connected and ports 1 and 4 sealed, as shown in Figure 2, or simply by inverting the gasket 8, ports 1 and 4 may be connected and ports 2 and 5 sealed.

Within each unit a diaphragm 10 extends completely across the housing so as to divide said housing into two chambers A and B. A one-way valve constituted by conical element 15 having an orice 14 therein is placed at the center of each diaphragm l0. A valve seat 12 is mounted beneath Valve l5 on supporting spokes 16, best seen in outline form in Figure l. When the pressure in the chamber B is higher than the pressure in the chamber A, the diaphragm l0 lifts and the chambers are connected by the oriiice 14.

For simplicity of illustration, ports 1 and 4 have been omitted from Figure 3, thus indicating that -those portsV would be sealed by the gaskets 8 when the system is arranged to select the lowest pressure. Similarly, the omission `of ports 2 and 5 from Figure 4 indicates that those ports would be sealed by the gaskets 8 whenever the system is arranged to select the highest pressure.

As illustrated in Figure 3, the lowest pressure of a group of variable pressures is selected by connecting the variable pressures to `the ports 3. Port 2 of unit housing I is connected to a source of fluid at a pressure equal to or greater than the highest pressure ever expected through any of the ports 3. The port 2 in unit I permits pressure to bleed slowly inwardly through a small orifice to be distributed to all of the chambers B which, for this application, are connected by aligning the ports 7 of the gaskets 8, and ports 2 and 5 which adjoin one another. As soon yas the pressure within the chamber B builds up to the lowest pressure in any chamber A, the one way valve in ythat unit opens and allows fluid to pass from chamber B to chamber A. The controller connected to that particular chamber A, through its port 3, has the capacity to bleed oli any increase in pressure much more rapidly than the aforementioned orifice in port 2, unit I, can build it up. Therefore a balance is reached and the pressure in the connected chambers B becames equal to the lowest pressure in the individual chambers A. This pressure is then `transmitted through `the port 6 of unit I.

As illustrated in Figure 4, the highest pressure of a group of variable pressures is selected by connecting the variable pressures to the ports 6. Port 1 of unit I is fitted with a small orice 17 which leaks gas to the atmosphere. Chambers A ,are all connected to one another through the gasket ports 7, which in this case are aligned with ports 1 and 4 in adjacent units. Therefore, the pressure in the chambers A is equal to the highest pressure in a chamber B, since the latter has opened its diaphragm valve and is responsible for the pressure in the chambers A. The aforementioned leak orifice l7 in port l of unit I, leaks gas much slower 6 can supply it. Therefore, pressure within the chambers A may be maintained and can be transmitted anywhere through the port 3 of unit I. The purpose of the bleed orifice 17 in the port 1 of unit I is to allow the pressure in the chambers A -to lower itself in step with the maximum pressure in chamber B when it lowers.

I claim:

1. Apparatus for the selection and transmission of an extreme uid pressure from amongst a plurality of variable fluid pressures, comprising a plurality of similar housings, vmeans dividing each of said housings into a first sealed chamber fand a second sealed chamber, a one-way valve in each of said housings to permit uid to ilow between said first and second chambers in but asingle direction, means connecting said irst chambers each to individual sources of variable uid pressure, the extreme pressure of which is to be selected and transmitted, means interconnecting each of said second chambers to provide a common chamber, means including a bleed orifice for providing continuous ow within said common chamber thereby permitting said common uid pressure and the extreme fluid ypressure from amongst said plurality of variable uid pressures to reach an equilibrium, and means for transmitting said common uid pressure to a remote point for utilization, said common fluid pressure being equal to the extreme pressure from amongst said plurality of Variable pressures.

2. Apparatus claimed in claim l wherein said means dividing each of said housings comprises a lexible diaphragm.

3. An apparatus claimed in claim 2 wherein said oneway valve is comprised by a conical element mounted on said diaphragm and having an aperture extending through said element and said diaphragm, and a valve seat xed opposite said conical element so that exure of said diaphragm Will move said element into engagement with said seat.

4. Apparatus for selecting and transmitting the highest pressure from amongst a group of variable fluid pressures, comprising a plurality of similar housings, each housing being divided into a rst chamber and asecond chamber and having a one-way valve interconnecting said first chamber with said second chamber, said valve permitting uid to ow only from said first chamber to said second chamber, means connecting said first chambers each to individual sources of variable uid pressure, the highest pressure of which is to be selected and transmitted, means interconnecting each of said second chambers to provide a common chamber, means for venting fluid from said common chamber, said venting means including a flow limiting orifice for maintaining the uid pressure within said common chamber equal to the pressure ofthat particular one of said first chambers from whence flow occurs, -said pressure within said common chamber being equal to the highest pressure from amongst said plurality of Variable pressures, and means for transmitting said pressure within said common chamber to a remote point for utilization.

5. An apparatus for selecting and transmitting the lowest pressure from amongst a group of variable uid pressures, comprising a plurality of similar housings, each housing being divided into a first chamber and a second chamber and having a one-way valve interconnecting said first chamber with said second chamber, said valve permitting uid to flow only from said rst chamber to said second chamber, means connecting said second chambers each to individual sources of variable fluid pressure, the lowest pressure of which is to be selected and transmitted, means interconnecting each of said first chambers to provide a common chamber, means for admitting fluid to said common chamber, said last named means including a flow limiting orice for maintaining the uid pressure within the said common chamber equal to the pressure of that particular one of said second chambers connected to the individual source of fluid pressure which provides the lowest pressure from amongst said group of pressures, and means for transmitting said pressure within said common chamber to a remote point for utilization.

References Cited in the le of this patent UNITED STATES PATENTS 1,922,512 Weingartner Aug. 15, 1933 2,516,333 Moore July 25, 1950 2,518,244 Moore Aug. 8, 1950 2,606,066 Thompson Aug. 5, 1952 2,638,921 Caldwell et al. May 19, 1953 2,643,663 Gold et al. June 30, 1953 2,778,373 .Taquith Jan. 22, 1957 

